Stereocameras



July 15, 1958 F. PERLIN 2,843,030

STEREOCAMERAS i Original Filed Nov. l. 1952 7 Sheets--SheetI 1 Trad .'FrZm July 1.5, 1958 F. PERLIN 2,843,030

STEREOCAMERAS Original Filed Nov. l. 1952 7 Sheets-Sheet 2 Mdmfw F.PERLIN STEREOCAMERAS July 15, 1958 '7 Sheets-Sheet 3- Orginal FiledNoir. l. 1952 July 15, 1958 FQ PERLIN u l 2,843,030

sTEREocAMERAs Original Filed Nov. 1, 1952 7 Sheets-Sheet 4 MLM?,

July 15, 1958 F. PERLIN sTEREocAMERAs Original Filed Nov. 1. 1952 '7S11eec.s-St1ee1l 5 July 15, 1958 F. PERLIN 2,843,030

.STEREOCAMERAS Original Filed Nov. 1. 1952 7 Sheets-Sheet 6 imdmw TradPer Zm July 15, 1958 Original Filed Nov. l. 1952 F. PERLIN STEREOCAMERAS'7 Sheets-Sheet '7 cocKED POSITION artisans srisnnocarvrnnas inc.,

313,153. Serial No.. 42.33%?,

Ciainis. (Cl. 95ml@ The present invention relates to cameras and moreparticularly to an improved stereocamera. This applica-- tion is adivision of my parent application, Serial No. 318,153, filed on Novemberl, 1952.

One object of this invention is to simplify the mechanism of astereocamera and reduce the number of its parts; and as a corollary, toreduce the cost of stereocameras without sacriicing good performance.

Another object of this invention is to provide a simple positive drivefrom the film indexing knob to the shutter cooking mechanism throughwhich each indexing advance of the iilm automatically cocks the shuttermechanism.

An important object of' this invention is to so construct the drive bywhich the iilm indexing mechanism actuates the shutter mechanism that aprescribed relationship between the locations of the exposed areas ofthe iilm and the perforations in the film is automatically assured.

Another object of this invention is to provide means for releasing thefilm indexing mechanism so that the roll of lm may be rewound, after itis exposed, without moving the shutter mechanism.

Other objects of the invention will be apparent herein* after from thespecification and from the recital of the appended claims.

in the drawings:

Fig. l is a perspective view of a stereocamera constructed according toone embodiment of the invention;

Fig. 2 is a vertical cross section through Fig. 1 on the plane of theline 2 2 and looking in the direction of the arrows;

Fig. 3 is a section also on the plane of the line 2-2 in Fig. 1.,duplicating, but on an enlarged scale, part of the structure shown inFig. 2;

4 is a longitudinal section through Fig. 1 on the plane of the line 4--4and looking in the direction of the arrows;

Fig. 5 is a section through Fig 4 on the plane of the line ith-S lookingin the direction of the arrows and illustrating particularly thediaphragm mechanism;

Fig. 6 is a detail section through Fig. 4 on the plane of the line 6-o,looking in 'the direction of the arrows and to illustrate the manner inwhich the shutters and diaphragms are mounted and related to the lightentry apertures of the camera; v

7 is a section through Fig. 4 substantially on the plane of the line 7-7and looking in the direction of the arrows;

Fig. 8 is an exploded perspective view of the camera with the front walland front mechanism removed and with the top cover shown separated fromthe camera body;

Fig 9 is a perspective View of the inner face of the front Wall of thecamera and the shutter mechanism mounted thereon;

Fig. 10 is an exploded perspective view of the shutter cookingmechanism;

ice

Fig. 11 is a perspective View illustrating the camera from the rear andtop but with the rear cover removed and shown separated from the camerabody; and

Figs. l2, 13 and 14 are plan views of the inner face of the front wallof the camera and the shutter mechanism mounted thereon and illustratingthe shutter mechanism parts respectively in cocked, post-exposure, andcocking positions, parts of said views being broken away to betterillustrate details.

Referring now to the accompanying drawings in which like numeralsindicate like parts throughout the several views, the numeral 5designates generally the body of a stereocamera constructed according toone embodiment of this invention and which is preferably formed as a diecasting. The front face of the body has a cavity 6 (Fig. 8) in itsmiddle portion to accommodate the shutter cooking mechanism of thecamera indicated generally by the numeral 7 (Fig. 3). At opposite sidesof this cavity 6 the body has a pair of light entry apertures t5 (Fig.8) leading to rearwardly facing exposure chambers 9.

The'film F (Fig. 4) to be exposed passes across the back face of thebody from a cartridge 10 mounted in a rearwardly opening pocket l1 atone end of the body to a spool 12 rotatably mounted in a pocket 13 whichalso opens to the rear face of the camera but at the opposite end of thebody. The iilm thus closes the back of each of the two exposure chambers9 to be impinged by light admitted into these chambers.

Light is admitted into the exposure chambers through lenses indicatedgenerally by the numeral 14 (Figs. 1 and 4) under control of a pair ofshutters l5 (Fig. 9). The shutters and lenses, as well as the shuttercooking mechanism 7, are mounted upon a removable front wall i6detachably held in position across the front face of the camera body byscrews 17 (Fig. l). As will appear more fully hereinafter, by mountingthe entire front mechanism, which includes the shutters, the shuttercocking mechanism, the diaphragms and the means for adjusting them uponthe front wall 16, the entire front mechanism of the camera may becompletely tested for all its functions before assembly thereof with thecamera body.

The back of the camera is closed by a cover 18 (Fig. l1) which isflanged and shaped to snugly t the back face of the camera body Where itis removably held in place by a rotatable latch 19. This latch consistsof a pair of oppositely extending arms 2li fixed to the hub 21 of alarge diameter knurled knob 22 overlying the center of the cover, thehub 21 passing through and being journaled in a hole in the cover. Uponrotation of the knob the ends of the arms 20 are engageable under a pairof strap-like keepers 23 secured to the body.

The back face of the camera body is U-shaped in cross section to provide.a film receiving track leading from the cartridge pocket 11 to thereceiving spool pocket i3. At its opposite sides the lilm track haslongitudinally extending, slightly elevated parallel coplanar lands orledges 24 upon which the perforated marginal edge portions of the lmride with the sensitized portion of the film clear of the interveningtrack bottom 25. A pressure plate 26 resiliently carried by the backcover 18 to which it is secured by a leaf spring 27 holds the iilmfirmly on the track portions 24 along the entire length thereof.

in loading the camera with lm, the rear cover plate 18 obviously must beremoved, and upon such removal a fresh film cartridge 10 (Fig. 4) isreadily placed in position in its pocket 11 and the free end of the filmdrawn from the cartridge and `attached to the spool l2. As is customarythe placement of a film cartridge 1d in its pocket lll entails endwisewithdrawal of a rewind stem 23 (Figs. 7 and 8), the outer end of whichhas a rewind knob 29V fixed thereon. The stem 28 is freely rotatably andslidably mounted in a bearing formed directly in the top wall 3G of thecamera body, and axial outward withdrawal thereof is limited by a collar3l on its inner bifurcated end. After the cartridge is in position thestem 28 is, of course, pushed back in and drivingly engaged with thespool of the cartridge to enable rewinding the film after the same hasbeen fully exposed.

The spool 12 upon which the film is wound with each indexing thereoffrom one exposure position to the next is rotated by turning a knob 32.This knob is joined to a shaft 33 journaled in bearings in the top andbottom body walls 3i) and 34, respectively, and upon which the spool isfrictionally secured. Any suitable friction means may be employed forthis purpose but in the present instance a small spring pressed ball 32seated in a radial socket in the shaft bears against the bore or thespool.

1t is, of course, essential that the film be advanced exactly the samedistance with eac-h indexing thereof. Hence, the film advancing torqueapplied to the knob 32 is transmitted to the film by a pair of sprocketwheeis 35 projecting through access holes 36 in the track portions 2d(Figs. 2 and 1l) and meshing with the perforations in the marginal edgesof the film (Figs. 2 and 4). During the indexing of the film thesesprocket wheels are turned a definite amount determined by timing meansin the shutter cocking mechanism 7 which, as will be later explained,makes it impossible to trip the shutters until the film has been fullyindexed.

The sprocekts 35 are fixed upon a shaft 37 (Fig. 7) freely rotatablysupported from the top and bottom body walls 3@ and 3d, respectively.The mounting for the bottom end of the shaft 37 comprises a pointedcenter 3% threaded in the bottom wall 34 and locked in place by a setscrew 39. The top end of the shaft 37 is rotatably supported by beingdrivingly attached to the hub 4Q of a gear Li1 journaled in the top bodywall 39.

The top wall 30 of the camera body is formed with an upwardly facingcavity 42 and located in this cavity is a train of gears (Figs. 7 and 8)connecting the sprocket gear 41 with a main drive pinion 43. The drivepinion is fixed to the spool shaft 33 and in fact constitutes theconnection between the shaft and the indexing knob 32. The train ofgears consists of an idler gear dd meshing with the pinion d3 and freelyrotatably journaled upon a trunnion 45; a counter gear 46 meshing withthe idler gear i4 and journaled upon a trunnion 47; and a release gearit meshing with the counter gear 46 and the sprocket drive gear 41 andjournaled upon a trunnion 49.

The idler gear 44, in addition to forming part of the described geartrain, also coacts with `a spring pawl Sii to restrain the indexing knob32 against retrograde rotation. Attention is directed to the fact thatthe mounting of the spring pawl does not interfere with axial placementof the gear 44 upon its trunnion d5 or removal therefrom.

All of the gears of the gear train, including the drive pinion i3 andthe shaft 33 to which it is fixed, are held in place by a cover 51removably secured across the open top of the cavity 4Z; and to enableremoval of the cover 51 for access to the gears both of the knobs 32 andZ9 are removable from their respective shafts.

The counter gear 46 has a unidirectional torque transmitting connectionwith a dial 52 journaled 1n the cover plate and exposed on the exteriorthereof. An arrow on the dial coacts with graduations on the surroundingportion of the cover, delineated in film footage or numbers of exposureto indicate the amount of unexposed film remaining in the camera. Theunidirectional driving connection between the counter gear and its dialis preferably provided by a conventional Wafer-type pawl 53 confinedbetween and coacting with ratchet yteeth on the adjacent faces of thegear and dial. Y,

By virtue of the geared driving connection between 4. the film indexingknob 32 and the sprocket wheels 35 it follows that the film will bepositively withdrawn from the cartridge with each indexing actuation ofthe knob to advance the film from one exposure position to the next; andthough the spool 12 is also turned with each film indexing rotation ofthe knob its rotation is not relied upon to index the film but merelyserves to prevent slack in the length of film between the spool and thesprocket w-heels. To assure this result despite the varying effectivediameter of the spool as the film is wound thereon, the speed ratiobetween the shaft 33 and the sprocket wheels 35 is such that the shaft33 always turns faster than necessary to drive the spool at a rate tokeep tension upon the length of film extending between the sprocketwheels and the spool; this differential in speed being permitted by theimpositive nature of the driving connection between the shaft 33 and thespool.

After the entire roll of film has been exposed it must be rewound ontothe cartridge spool which, of course, entails retrograde rotation of thesprocket wheels. To allow such retrograde rotation of the sprocketwheels is one of the functions of the release gear To this end the gear48 is slidable axially upon its trunnion 49 to and from meshingengagement with the sprocket drive gear #in and is yieldingly held inits position meshing with the gear if by a compression spring The thrustof the spring is carried by the cover plate 51 to which it istransmitted by a release button 55 slidably mounted in a hole in thecover plate and provided with a flange 55 interposed between the top ofthe gear and the underside of the cover plate. As will be evident,depression of the release button 55 frees the sprocket wheels 35 forretrograde rotation so that the film may be rewound upon the cartridgespool by turning the rewind knob 29.

One of the features of this invention is that each advance of the filmfrom one exposure position to the next automatically cocks the shuttermechanism. To this end the sprocket wheel shaft 37 has a bevel gear 56(Figs. 2, 4, 7, 8 and 11) fixed thereon to mesh with a bevel gear 57(Figs. 2, 3, and 9) on the shutter cocking mechanism 7. Preferably,though not necessarily, the bevel gear 56 and the lower sprocket wheel35 are directly connected to one another.

The shutter cocking mechanism, as hereinbefore indicated, is carried bythe removable front wall llo (Figs. 4 and 9) of the camera so that thedriving connection between the film indexing mechanism and the shuttercocking mechanism and which is provided by the meshing bevel gears, isautomatically established with the attachment of the front wall 16 tothe camera body.

The front wall i6 comprises a cover plate 53 and a mechanism mountingplate 59 secured to one another in parallel spaced relation. The spacebetween these plates accommodates the diaphragms to be hereinafterdescribed, and the lenses are, of course, mounted upon the cover plate.Both of the plates have light entry apertures to lzlin with theapertures in the front wall of the camera The shutters 15 closelyoverlie the rear face of the mechanism mounting plate 59 (Fig. 9) andare mounted thereon to rotate in one direction about fixed axes sopositioned with respect to the light entry apertures that as they rotatetheir windows dii are momentarily aligned with the apertures to admitfilm exposing light. Each shutter has a gear 61 fixed with respectthereto and preferably formed by teeth cut directly into the peripheryof the disc which provides the shutter, and the two shutter gears arepositively drivingly connected by an intermediate shutter drive gear 62also overlying the rear face of the mechanism mounting plate S9 andmounted thereon for rotation about a fixed axis.

The mounting for the shutter drive gear comprises a multi-diameter postor shaft 63 (Figs. 2, 3, 9, 12, 13 and 14) passing through and rigidlyfixed to the mechanism mounting plate by having the edge portion of thehole estense in the plate through which it passes clamped between aflange 6ft on the post or shaft and a swedged portion 65. The portieri66 of the rearward projection of the post or shaft has the hub 62 (Figs.3 and 10) of the shutter drive gear freely rotatably journaled thereonand held in place by being confined between the ange 64 and a timingdisc 67 freely rotatably journaled upon the reduced rear end portion 68of the post or shaft; the timing disc being held against axialdisplacement from the post or shaft 63 by means of a lC-washer 69 fixedto the rearmost end of the post or shaft.

The shutter drive gear 62 has a ring gear 7@ formed integrally therewithand projecting from its rear face to surround the hub 62. The annularspace thus provided between the ring gear 7d and the hub 62 accommodatesa coiled torsion spring 711. One end 72 of this spring is anchored tothe shutter drive gear 62 and its other end 73 is anchored to the timingdisc 67 by being hooked onto an abutment in the form of a pin 74projecting from the front face of the disc. The abutment 74 is receivedin the annular space between the ring gear 70 and the hub 62' and ispositioned to collide with an abutment 75 projecting radially inwardlyfrom the ring gear 70. Such engagement between the two abutments occurswhen the shutter cooking mechanism has been brought into its fullycocked condition, shown in Figure 12, as will be hereinafter more fullydescribed.

Since one end of the spring 71 is anchored to the shutter drive gear 62and its other end is attached to the timing disc e?, it follows thatupon relative rotation of these parts in the proper direction the spring7l may be wound up or tensioned. To effect such relative rotationbetween the shutter drive gear 62 and the timing disc 67, means areprovided to hold the gear against rotation while the disc is turned as aconsequence to indexing of the film. This holding function is performedby what may be referred to as a post-exposure stop and which comprisesan abutment or pin F76 (Figs. 9 and 12) and the edge of the timing disc67. The abutment or pin 76 is carried by a timing gear 7'7 freelyrotatably mounted upon the mechanism mounting base and meshing with thering gear 7i) and travels in a circular orbit which crosses the edge ofthe timing disc 67. Hence, as the pin 76 is carried along by the timinggear it collides with the edge of the disc and thereby restrains thetiming gear and hence the shutter drive gear and the shutters againstturning while permitting the timing disc to turn. With the engagement ofthe pin '76 with the edge of the timing disc the shutters are in theirpost-exposure positions to which they have been previous film exposure.

This post-exposure position of the parts is maintained until the timingdisc 67 is rotated, by the film indexing mechanism, far enough to aligna gate or notch 7S in its edge with the pin 76. With the entry of thepin 76 into the gate or notch the timing gear is again free to turnunder the influence of the spring, but it should be noted that at thistime the rotation lof the timing gear 77 and with it the rotation of theshutters is under the control of the timing disc. This control ismaintained until the very instant the disc has turned far enough toallori7 the pin 76 to leave its gate or notch 78; and as will appearfrom a comparison of Figs. 12 and 14, this position of the parts is notreached until the indexing of the film is complete.

The termination of the film advance by the actuation of the indexingmechanism is defined by the engagement of an abutment i9 (Fig. 10) onthe gear 62 with a trigger stop tt@ (Figs. 9, l2, 13 and 14) and thecollision of the pin 7d on the timing disc with the abutment 75 on thethen stationary ring gear 70. Since the pin 76 does not leave the gateor notch 78 until'the instant the abutment 79 comes up against thetrigger stop 8b to thereby not only stop the film advance but alsodefine the cocked position of the shutters, an important corollary ofrotated by the shutter'spring during the d the action just described isthat the shutters cannot be released from their cocked positions untilthe film has been fully indexed.

The bevel gear 57 (Figs. 3 and 9) through which the drive from the lmindexing mechanism is carried into the shutter cooking mechanism ismounted upon the hub of the timing disc 67, and is drivingly connectedwith the timing disc through a unidirectional clutch which in thepresent instance comprises a wafer-type pawl 81 (Figs. 9 and 10)coacting with ratchet teeth on the adjacent faces of the gear and disc.The unidirectional aspect of this connection between the gear and thetiming disc permits rewinding of the film Without interference from theshutter cooking mechanism since it allows retrograde rotation of thebevel gears along with the sprocket wheels "'l the timing disc remainsstationary.

rough the pawl 81 is intended to yield during retrograde rotation of thebevel gears and thus allow the timing disc to remain stationary duringrewinding of the film, to assure this result a light leaf spring typepawl 82 (Figs. 2, 9, 12, 13, 14) is provided. This pawl S2 is mounted onthe base 59 and has its free end engaging the teeth of the shutter drivegear 62 to hold the gear against retrograde rotation without, however,resisting its forward, spring-produced rotation during movement of theshutters from their cocked positions.

The trigger stop 8) (Figs. 9, 12, 13 and 14) is formed by one end of alever medially pivoted upon the mechanism mounting base as at 83 and isyieldingly held in its operative position by a torsion spring 84. Theoperative position of the stop is defined by the engagement of a stud 85carried by the lever with the top of a hole 86 in the mechanism base,the hole being large enough to allow the lever to be rocked to and fromits operative position. To enable the lever to be moved to release theshutters the stud has an actuating knob S7 (Fig. 1) mounted thereon andaccessible at the front of the camera.

Between the cover 58 and the mechanism mounting plate 59 is a pair ofdiaphragm discs 88 (Fig. 5) each of which has three differentprogressively larger holes 39, and 91 adapted to be selectively broughtinto alignment with the light entry apertures by rotation of the discs.l'n keeping with the purpose of this invention to reduce the number ofparts and achieve utmost simplicity, the diaphragm discs are mountedupon the mechanism base by the same means which mounts the shutters. Thecommon support for each shutter and the associated diaphragm disc may beconstructed in any suitable manner. It may be a simple rivet, but in thestructure shown it comprises a screw 92 (Fig. 9) stepped to provide ajournal for the yshutter disc and a headed stud 93 (Fig. 5) into whichthe screw is threaded and which, like the screw, is stepped to provide ajournal for the diaphragm disc, it being understood that the mechanismmounting plate is clamped between the journal providing portions of thescrew and stud.

The two diaphragm discsare geared together by means of a diaphragmadjusting gear 94 which meshes with gear teeth 95 on the peripheries ofthe diaphragm discs. Again with a view toward achieving simplicity and areduction in the number of parts, the diaphragm adjusting gear 94 isrotatably mounted upon the forward projection 96 of the post or shaft 63(Figs. 2 and 3) upon which the shutter drive gear, the timing disc andthe bevel gear 57 are journaled. Thus the mounting for the diaphragmadjusting gear comprises a hub 97 to which the gear is fastened andwhich has a flange 93 overlying the inner face of the cover 58. Theprotruding end of the hub 97 has a diaphragm adjusting knob 99 fastenedthereto and in the underside of this knob is a detent pin 166 whichcoacts with detent holes 1M in the cover to indicate the differentpositions of the diaphragm discs at which their holes are selectivelyaligned with the light entry apertures. K

This manner of mounting and driving the diaphragms 7 not only assuressynchronized adjustment of the two diaphragm discs but also results in avery compact, neat appearance for the front of the camera with thediaphragm adjusting knob located between the two lens assemblies;

The stop abutment 76 (Figs. 9 and 12 to 14) on the timing gear 77 inaddition to forming part of the postexposure stop (by virtue of itsengagement with the edge of the timing disc 67) also provides apositively synchronized flash switch actuator. To this end a springcontact finger MZ is mounted on but insulated from a post fli projectingfrom the back of the mechanism mounting base 59 with the free end of thecontact finger lying in the path of the pin 76. The contact finger 102is connected in one side of a flash bulb circuit, the other side ofwhich is grounded. Hence, as the pin, which of course is also grounded,travels along its orbit upon release of the shutters and transientlyengages the contact finger, the fiash bulb circuit is momentarilyclosed. The placement of the Contact finger llilZ is such that thiscompletion of the flash bulb circuit is correctly timed and, of course,exactly synchronized with the film exposing rotation of the shutters.

To connect the ungrounded contact finger M2 into the fiash bulb circuitit is electrically connected as at fdd with a plug socket M5 mounted onthe top of the camera and adapted to receive the plug on the end of theconnecting wire of a flash bulb attachment, not shown. This connectionMP4 between the contact finger and the plug socket must not interferewith the attachment of the front mechanism as a complete sub-assembly-Hence, it is formed in the marmer of a plug-in jack as best shown inFig. 2.

While the View finder of the camera is a detail which can beincorporated in any desired manner, in the present invention it consistssimply of a cored opening 106 (Fig. 7) through the die cast body of thecamera in line with suitable lenses liti7 (Figs. l and 8) and N8 (Fig.ll) in the front and back camera walls, respectively.

An important feature of the invention involves the manner in which thedriving connection is established between the film indexing means andthe shutter mechanism and more particularly in the design of theunidirectional clutch provided by the wafer-type spring pawl iii (Fig.l0) and the ratchet teeth on the bevel gear V 57 and the timing disc 67.The importance of this feature results from the fact that the cuttingand trimming of the exposed and developed film preparatory to mountingthe resulting transparencies is now done on auto matic machines whichfeed the film forward to the cutting knives by sprockets engaging in.the perforations in the film. Obviously, therefore, unless a prescribedrelationship is maintained between the locations of the exposed areas ofthe lm and the perforations in the film, there is no assurance thatparts of the transparencies will not be cut off during the cutting andtrimming of the film; and since the distance between perforations is asubstantial fraction of the width of each transparency, a considerablepart of each picture would be cut off if maximum displacement existedbetween the locations of the exposed areas and the perforations.

It is, therefore, of utmost importance that, when the camera is firstloaded with film and is indexed to its rst exposure position, thesprocket teeth engaging the film at the time it reaches its indexedposition shall be exactly centered between the two areas of the film inposition to be exposed.

in stereocameras heretofore available it was necessary to manuallypreset the sprocket during the loading of the camera in order to assurethis desired result, but with the present invention this is accomplishedautomatically by the simple expedient of properly correlating theangular positions of the teeth on the sprocket wheels with thedefinitevdriving positions of the two elements of the unidirectionalclutch between the bevel gear 57 g and the timing disc 67. Thisrelationship is attained by having the number of ratchet teeth withwhich the wafer-type pawl 81 coacts equal to the number of teeth on thesprocket wheels or some sub-multiple thereof; and in the `structureshown there are ten teeth on the sprocket and ten ratchet teeth on boththe bevel gear 57 and the timing Vdisc 67.

Consequently, regardless of the position in which the sprocket wheelsare left after rewinding an exposed film, quent initial indexing of anew film automatically cs a fishes the correct relationship between theindexing mechanism and the shutter mechanism to assure that the sprocketteeth engaging the film when the same is ndexed will be exactly centeredbetwen the areas film in position to be exposed. In other words, 1rewinding of the film happens to leave the bevel gear 57 in a positionatwhich the unidirectional clutch is not fully engaged, the shuttermechanism of course remains at rest until the film has been advanced farenough to positively engage the clutch but since the definite drivingpositions of the clutch are the same in number as the teeth on thesprocket and bear the proper angular relationship thereto, the taking upof this slack in the clutch during the initial indexing of thefilrnautonatically establishes the correct relationship between the filmindexing mechanism and the shutter mechanism.

Assuming that the camera is loaded with film and in all respects isready for use, it will operate as follows: The appropriate diaphragmopenings are brought into alignment with the light entry apertures byrotation of the knob 99 (Fig. 1) which carries an arrow to coact withthe designations sunny, hazy and shadyf The film is then advanced byrotation of the film indexing knob 32 to bring it to its first exposureposition. During this film indexing action torque is positivelytransmitted to the sprocket shaft 37 from the knob 32 through the geartrain comprising the meshing gears 43, 44, 46, 4.13 and 41. Theconsequent rotation of the sprocket draws the film from its cartridge 10and advances the same a predetermined distance. At the same time thepositive rotation of the sprocket shaft 37 transmits torque to theshutter cocking mechanism through the meshing bevel gears 56 and 57 andthe unidirectional clutch 81 between the bevel gear 57 and the timingdisc 67.

Since the shutter spring 71 is at all times under some degree oftension, the stop pin 76 is in engagement with the edge of the timingdisc 67, defining the post-exposure position of the shutters, asrotation of the bevel gear 57 begins to turn the disc.

The engagement of the stop pin 76 with the edge of the timing disc 67not only holds the shutters against turning from their post-exposurepositions but also restrains the timing gear 77 and the ring gear 70against turning so that as the bevel gear 57 and the timing disccontinue to turn the resulting relative rotation between the timing discand the ring gear 7i) winds up and increases the tension upon the spring71. As this relative rotation between the timing disc 67 and the gearprogresses and the tension on the spring increases the gate or notch 78in the edge of the timing disc moves into alignment with the stop pin 76whereupon the pin enters the gate and the gears begin to revolve undercontrol of the timing disc. By this time the spring 71 is almost fullytensioned.

After a few more degrees of rotation during which the tensioning of thespring is completed, the pin 76 moves out of the gate or notch 78 tothus free the shutters from restraint by the timing disc. However, atthis instant the abutment 79 on the shutter drive gear 62 comes upagainst the trigger stop 80 and the abutments 74 and 7S engage. Thefirst of these two engagements defines the cocked positions of theshutters and holds the shutter mechanism in its cocked condition. Thesecond stops the film advancing actuation of the indexing mechanism.

Since the lenses are of the fixed focus type, the camera is now ready totake a picture, and to doY so nothing more need be done than to pointthe camera at the scene to be shot using the viewfinder in the customaryway, and then depress the shutter release button S7. Actuation of therelease button frees the shutters for spring produced rotation and sincethe shutters are constrained to concomitant rotation, they move in exactsynchronization so that both pictures are taken at exactly the sametime. This spring produced rotation of the shutters is stopped by theengagement of the pin 76 with the edge of the timing disc 67 whereuponthe parts are again in their post-exposure positions so that the lmindexing mechanism may be again actuated.

When the entire roll of film has been exposed, the rewind release button55 is depressed and held down while the rewind knob 29 is turned toretract the film and rewind it upon the cartridge spool.

From the foregoing description taken in connection with the accompanyingdrawings, it will be readily apparent to those skilled in the art thatthis invention provides a stereocamera which possesses many advantagesover such cameras heretofore available, and that most of theseadvantages fiow from the fact that simplicity and reduction in thenumber of parts characterizes its construction.

While the invention has been described in connection with a certainembodiment thereof, it will be understood that it is capable of furthermodification, and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come within known or customary practice in the artto which the invention pertains and as may be applied tothe essentialfeatures hereinbefore set forth and as fall within the scope of theinvention or the limits of the appended claims.

Having thus described my invention what I claim is:

1. In a stereocamera of the type having two separate exposure aperturesfor making simultaneously two separate exposures on a photosensitivemedium, the combination of a pair of shutters, each positioned,respectively, in front of one of said exposure apertures, means mountingthe shutters for rotation about separate, spaced, fixed parallel axes, apositive motion transmitting connection between the shuttersconstraining them to concomitant rotation, a shutter spring acting uponsaid connected shutters, a film indexing mechanism comprising a sprockethaving teeth adapted to mesh with perforations in the ilm to positivelyadvance the film upon rotation of the sprocket, unidirectional actuatingmeans for turning said sprocket in the film advancing direction, meansfor disengaging the sprocket from said actuating means to allowretrograde rotation of the sprocket and thus enable retraction of thefilm, a driving connection between the sprocket and the connectedshutters and the shutter spring for cocking the shutters and tensioningthe spring with each indexing of the film, said driving connectionincluding a pawl and ratchet capable of transmitting shutter cocking andspring tensioning motion during advance of the film while leaving theshutters and shutter spring unaffected during retraction of the film,stop means for arresting shutter cocking and spring tensioning motionand thereby limiting film advance to thus define the indexed position ofthe film, and the number of teeth on the ratchet being equally divisibleinto the number of teeth on the sprocket so that despite the position inwhich the sprocket is left after a retraction of the film duringsubsequent film indexing the sprocket will stop with its teeth inexactly the same positions at the completion of each film advance.

2. In a camera in which the indexing of the film from one exposureposition to the next also cocks the shutter mechanism of the camera, thecombination of a shutter mounted for rotation about a fixed axis,mechanism including a manually operable actuator on the exterior of thecamera for indexing the film, a post-exposure shutter stop comprising adisc rotatable about a fixed axis and positively drivingly connectedwith the film indexing means to turn with each indexing of the film, andan abutment radially spaced from and rotatable about a fixed axisparallel to the axis of rotation of said disc and so spaced from itsaxis of rotation as to collide with the edge of said disc and be therebyheld against further movement along its orbit, said abutment beingpositively connected with said shutter to move along its orbit wheneversaid shutter turns so that the collision of the abutment with the edgeof said disc holds said shutter against rotation in one direction, ashutter spring having one end connected with said shutter and its otherend connected with said rotatable disc so that rotation of said discwith respect to said shutter tensions said spring, means constrainingsaid disc to rotation in only that direction which so tensions thespring as to bias the shutter for spring produced movement from itscocked position to its postexposure position, said disc having a gate inits edge adapted to receive said abutment in one position of relativerotation of said parts to thereby enable the abutment to move beyond itspost-exposure stop position and accordingly allow said shutter to movefrom its postexposure position toward its cocked position, and triggermeans for releasably holding the shutter in its cocked position in whichit is maintained by the tension of said spring comprising an abutmentpositively connected with the shutter and rotatable about a fixed axis,a releasable stop biased to a position lying in the path of said lastnamed abutment, and a manually operable actuator connected with the stopfor moving it out of its position in the path of said abutment.

3. In a camera Vin which the indexing of the film from one exposureposition to the next also cocks the shutter mechanism of the camera, thecombination of a camera body, a mechanism base detachably secured to thecamera body, a shutter rotatably mounted upon the mechanism base, filmindexing mechanism carried by said camera body and including a manuallyoperable actuator on the exterior of the camera and a power take-offgear inside the camera rotatable with each indexing of the film, a discrotatably mounted upon the mechanism base for rotation about a fixedaxis parallel to that of the shutter, gear means drivingly connectedwith the disc and with said power take-off gear of the film indexingmeans so that the disc turns with each indexing of the film, a stopabutment rotatably mounted upon the mechanism base for rotation about afixed axis parallel to that of the disc, said stop abutment being spacedradially from its axis of rotation a distance such that its orbitcrosses the edge of the disc, means positively connecting said stopabutment with the shutter so that rotation of the shutter from itscocked position is accompanied by movement of the stop abutment alongits orbit and into collision with the edge of the disc to thereby holdthe shutter against further rotation in said direction, a shutter springhaving one end connected with the shutter and its other end connectedwith the disc, said spring being under tension and yieldingly urging theshutter in said direction to effect collision of the stop abutment withthe edge of said disc, means constraining the disc to rotation in onlythat direction in which rotation of the disc with respect to the shutterincreases the tension upon the spring, said disc having a gate in itsedge adapted to receive the stop abutment in one relative position ofrotation of said parts to thereby enable the stop abutment to movebeyond the position it occupies when it engages the edge of the disc andaccordingly allow the shutter to turn under the infiuence of the springfrom its position defined by the engagement of the stop abutment withthe edge of the disc toward the cocked position of the shutter, andtrigger means for releasably holding the shutter in its cocked positionin which it is maintained by the tension of its spring.

4. In a camera in which the indexing of the film from one exposureposition to the next also cocks the shutter mechanism of the camera, thecombination of a camera body, a mechanism base detachably secured to thecamera body, a shutter rotatably mounted upon the mechanism base, filmindexing mechanism carried by said camera body and including a manuallyoperable actuator on the exterior of the camera and a power take-offgear inside the camera rotatable With each indexing of the film, a discrotatably mounted upon the mechanism base for rotation about a fixedaxis parallel to that of the shutter, gear means drivingly connectedwith the disc and with said power take-off gear of the film indexingmeans so that the disc turns with each indexing of the iilm, a stopabutment rotatably mounted upon the mechanism base for rotation about afixed axis parallel to that of the disc, said stop abutment being spacedradially from its axis of rotation a distance such that its orbitcrosses the edgc of the disc, means positively connecting said stopabutment with the shutter so that rotation of the shutter from itscocked position is accompanied by movement of the stop abutment alongits orbit and into collision with the edge of the disc to thereby holdthe shutter against further rotation in said direction, a shutter springhaving one end connected with the shutter and its other end connectedwith the disc, said spring being under tension and yieldingly urging theshutter in said direction to effect collision of the stop abutment withthe edge of said disc, means constraining the disc to rotation in onlythat direction in which rotation of the disc with respect to the shutterincreases the tension upon the spring, said disc having a gate in itsedge adapted to receive the stop abutment in one relative position ofrotation of said parts to thereby enable the stop abutment to movebeyond the position it occupies when it engages the edge of the disc andaccordingly allow the shutter to turn under the influence of the springfrom its position defined by the engagement of the stop abutment withthe edge of the disc toward the cocked position of the shutter, triggermeans for releasably holding the shutter 1n its cocked position in whichit is main- "12 tained by the tension of its spring, said trigger meanscomprising an abutment connected with the shutter and rotatable about anaxis xed with respect to the mechanism base, a lever pivoted upon saidbase and biased to a position in which a part thereof lies in the pathof said abutment, and a manually operable actuator connected with thelever for rocking the same to a shutter releasing position.

5. A stereocamera using perforated film, and having spaced exposureapertures, a pair of shutters positioned, respectively, in front of saidexposure apertures and c011- nected for concomitant rotation onseparate, spaced, parallel axes, a rotatable shaft, a sprocket mountedon said shaft, said sprocket having peripheral teeth engaging theperfo-rations in said film, means for rotating said shaft to therebyindex said film, a driving connection between said shaft and said pairof Vconnected shutters, said driving connection comprising a pawl and aratchet capable of transmitting shutter cooking motion during advance ofthe film, and stop means for arresting shutter cooking motion andthereby limiting film advance to thus define the indexed position of thefilm, and the number of teeth on said ratchet being equally divisibleinto the number of teeth on the sprocket, so that despite the positionof the film during subsequent lilm indexing the sprocket will stop withits teeth in'exactly the same position at the completion of each filmadvance.

References Cited in the file of this patent -UNITED STATES PATENTS694,3644 Frachebourg Mar. 4, 1902 2,194,284 Kuppenbender Mar. 19, 19402,402,149 vCrumrineV June 18, 1946 2,476,576 Bachelder July 19, 19492,515,272 Smith July 18, 1950 2,522,214 Dreisbach Sept. l2, 19502,608,920 Smith Sept. 2, 1952

